Characterization of the squalene-rich Botryococcus braunii Abt02 strain     

CAO Min  ZHANG Fangfang  MAO Yunxiang  KONG Fanna  WANG Dongmei 《海洋湖沼学报（英文）》2019,(2):675-684

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Characterization of Pythium chondricola associated with red rot disease of Pyropia yezoensis (Ueda) (Bangiales,Rhodophyta) from Lianyungang,China     

Qiu  Liping  Mao  Yunxiang  Tang  Lei  Tang  Xianghai  Mo  Zhaolan 《中国海洋湖沼学报》2019,37(3):1102-1112

Pyropia yezoensis(formerly Porphyra yezoensis) is an economically important red alga that is cultured extensively in China. The red rot disease occurs commonly during Pyropia cultivation,causing serious economic losses. An incidence of red rot disease was found in a P. yezoensis farm from mid-November to mid-December 2015 at Lianyungang, Jiangsu Province, China. Histopathological examination revealed that the naturally infected thalli were infected apparently by a pathogen, leading to red rot symptoms. The causative agent was isolated and identified as the oomycete Pythium chondricola by morphological analysis and sequence analysis of the internal transcribed spacer and cytochrome oxidase subunit 1(cox1). In artificial infection experiments on the P. yezoensis blades, the P. chondricola isolate was able to cause the same characteristic histopathology seen in natural infections. P. chondricola grew well at a wide range of temperatures in the range 8-31℃, salinities at 0-45 and pH 5-9. In an orthogonal test used to determine the effects of environmental factors(temperature, salinity, and zoospore concentration)on infection, the data revealed that temperature was the most important factor to affect red rot disease development, with the optimal conditions for disease expansion being 20℃, 35 salinity, and a zoospore concentration of 10~6 zoospores/mL. The results obtained from the present study prompted us to set up a comprehensive epidemiological study on Pyropia, which will provide support to maintain the healthy development of the Pyropia industry in China.  相似文献   

Cloning and characterization of proliferating cell nuclear antigen gene of Alexandrium catenella (Dinoflagellate) with respect to cell growth     

HUANG Jian  LIANG Shan  SUI Zhenghong  MAO Yunxiang  GUO Hao 《海洋学报(英文版)》2010,29(3)

Harmful algal blooms (HABs) have been affecting negatively the shellfish and aquaculture industries around the world. Though a lot of efforts have been made to disclose the changes of environmental factors involved and their effects on the HABs events, the molecular mechanism of this process remains unclear. To address this problem, proliferating cell nuclear antigen gene (pcna) was isolated and characterized from Alexandrium catenella. It showed high homology to those of other dinoflagellates (89% and 91% homology to Pfiesteria piscicid and Pyrocystis lunula, respectively), and also 42%–43% homology to those of plant and animals. The expression level of pcna revealed by quantitative real time PCR was the lowest at the late lagging cell growth phase, increased to the highest at the late exponential phase, and then decreased at the stationary phase. Though the cell growth rate was also changing, no positive correlation between pcna expression level and cell growth rate was displayed throughout the whole cell growth stages (r 2 =0.024 6). However, the pcna expression level had the similar trend with the change of cell growth rate throughout the whole growing process, e.g., from increasing at the earlier cell growth stage to decreasing at the following stages, though slightly lagging to the latter.  相似文献   

Construction and characterization of a fosmid library for pathogenic bacterium <Emphasis Type="Italic">Vibrio anguillarum</Emphasis>     

韩一凡  莫照兰  茅云翔  肖鹏  李杰  郝斌  郭东升 《中国海洋湖沼学报》2009,27(3):519-526

Vibrio anguillarum is a common bacterial pathogen in fish.However,little is known about its pathogenic mechanism,in part,because the entire genome has not been completely sequenced.We constructed a fosmid library for V.anguillarum containing 960 clones with an average insert size of 37.7 kb and 8.6-fold genome coverage.We characterized the library by end-sequencing 50 randomly selected clones.This generated 93 sequences with a total length of 57 485 bp covering 1.4% of the whole genome.Of these sequences,58...  相似文献   

Cloning and Analysis of Calmodulin Gene from Porphyra yezoensis Ueda (Bangiales, Rhodophyta)     

WANG Mengqiang）  ））  MAO Yunxiang）  *  ZHUANG Yunyun）  ）  KONG Fanna）    SUI Zhenghong） ） College of Marine Life Sciences  Ocean University of China  Qingdao  P. R. China ） Institute of Oceanology  Chinese Academy of Sciences  Qingdao  P. R. China ） Graduate University of Chinese Academy of Sciences  Beijing  P. R. China ） Department of Marine Sciences  University of Connecticut  Groton CT  USA 《中国海洋大学学报(英文版)》2009,8(3)

In order to understand the mechanisms of signal transduction and anti-desiccation mechanisms of Porphyra yezoensiss,cDNA and its genomic sequence of Calmodulin gene (CaM) was cloned by the technique of polymerase chain reaction (PCR) based on the analysis of P. yezoensis ESTs from dbEST database. The result shows that the full-length cDNA of CaM consists of 603 bps including an ORF encoding for 151 amino acids and a terminate codon UGA, while the length of genomic sequence is 1231 bps including 2 exous and 1 intron. The average GC content of the coding region is 58.77%, while the GC content of the third position of this gene is as high as 82.23%. Four Ca2+ binding sites (EF-hand) are found in this gene. The predicted molecular mass of the deduced peptide is 16688.72 Da and the pI is 4.222. By aligning with known CaM genes, the similarity of CaM gene sequence with homologous genes in Chlamydomonas incerta and Chlamydomonas reinhardtii is 72.7% and 72.2% respectively, and the similarity of the deduced amino acid sequence of CaM gene with homologous genes in C. incerta and C. reinhardtii are both 71.5%. This is the first report on CaM from a species of Rhodophyta.  相似文献   

基于数字地形分析的火星地貌自动化分类方法   总被引：1，自引：1，他引：0  

王琤  胡鹏  刘晓航  李云翔 《武汉大学学报(信息科学版)》2009,34(4)

提出了基于纵坡面统计特征的火星地貌类型单元划分体系,详细阐述了地形特征因子及分类所需特征空间的选取建立过程.实验结果表明.以此为基础的火星表面地貌自动分类方法基本能与高程、影像信息反映事实相符.与目前公布的分类成果具有一定的可比性,达到了预期的研究目的.  相似文献   

内孤立波作用下FPSO动力响应特性     

张瑞瑞  张新曙  尤云祥  许忠海  刘建成  王晋 《海洋工程》2017,35(4):8-17

以KdV、eKdV和MCC理论的适用性条件为依据,利用内孤立波产生的瞬时速度和瞬时压力沿船体表面求面积分的方法分别计算浮式生产储油卸油装置(FPSO)内孤立波摩擦阻力和Froude-krylov力,再结合时域有限位移运动方程,研究了有限深两层流体中的内孤立波与带分段式系泊缆FPSO的相互作用问题。以东沙群岛某海域实测170 m振幅的内孤立波为对象,数值分析了在内孤立波作用下FPSO的内孤立波动态载荷、运动响应及其系泊张力的变化特性。研究表明,内孤立波会对FPSO产生突发的冲击,使FPSO产生大幅度水平漂移运动,导致系泊缆张力显著增大。在该振幅内孤立波作用下,FPSO受到的水平力最大可达56 t,垂向力最大可达1 961 t;纵荡位移可达47.62 m,系泊缆张力增加最大可达106.4 t。因此,在FPSO等深海浮式结构物的设计应用中,内孤立波的影响是不可忽视的。  相似文献   

珠江口持续性雾生消的环流特征和成因分析   总被引：1，自引：0，他引：1  

王婷  潘蔚娟  谌志刚  刘云香 《气象》2010,36(6):13-20

利用各种气象观测资料,研究了1980—2006年珠江口地区持续性雾的气候特征,并通过典型个例分析了持续性雾生消的环流特征和物理机制。主要结论有:珠江口地区持续性雾集中出现在10月至次年5月,尤其是春季出现概率最大;出现持续性雾的环流形势主要有3种:A型——低压或倒槽的东侧,B型——高压的底部或后部,C型——均压场;在持续性雾过程中,近地层暖湿平流的输入、浅层抬升、水汽弱辐合以及对流层中下部的"干暖盖"有利于饱和湿空气的凝结以及逆温层的维持,而伴随偏北风南下的干冷平流是雾消散的主要因素。  相似文献   

云南地基GPS观测大气可降水量变化特征   总被引：4，自引：1，他引：3  

符睿  段旭  刘建宇  孙绩华  王曼  陈新梅  刘云香 《气象科技》2010,38(4):456-462

利用2007年云南地基GPS站点观测资料,分析GPS反演的大气可降水量(PWV)变化特征,并用探空、实际降水量资料和GPS反演结果进行比较。结果表明:GPS/PWV能反映云南降水的季节变化特征,海拔较低的测站普遍比同期海拔较高的测站测得的GPS/PWV值高;GPS/PWV值与探空得到的大气水汽总量随时间演变趋势基本一致,其相关系数均达0.89;GPS/PWV变化周期和实际降水发生的周期基本相同,降水大多为GPS/PWV值连续增加达到峰值(或从峰值开始下降)后开始;GPS/PWV上升幅度较大或位于高位可作为连续性强降水过程出现的预报指标,但使用GPS/PWV峰值作预报指标时,还应考虑季节因素。  相似文献   

Aboveground net primary productivity of vegetation along a climate-related gradient in a Eurasian temperate grassland: spatiotemporal patterns and their relationships with climate factors   总被引：1，自引：0，他引：1  

Tian Gao  Bin Xu  Xiuchun Yang  Songqiu Deng  Yuechen Liu  Yunxiang Jin  Hailong Ma  Jinya Li  Haida Yu  Xiao Zheng  Qiangyi Yu 《Environmental Earth Sciences》2017,76(1):56

Accurate assessments of spatiotemporal patterns in net primary productivity and their links to climate are important to obtain a deeper understanding of the function, stability and sustainability of grassland ecosystems. We combined a satellite-derived NDVI time-series dataset and field-based samples to investigate spatiotemporal patterns in aboveground net primary productivity (ANPP), and we examined the effect of growing season air temperate (GST) and precipitation (GSP) on these patterns along a climate-related gradient in an eastern Eurasian grassland. Our results indicated that the ANPP fluctuated with no significant trend during 2001–2012. The spatial distribution of ANPP was heterogeneous and decreased from northeast to southwest. The interannual changes in ANPP were mainly controlled by year-to-year GSP; a strong correlation of interannual variability between ANPP and GSP was observed. Similarly, GSP strongly influenced spatial variations in ANPP, and the slopes of fitted linear functions of the GSP–ANPP relationship increased from arid temperate desert grassland to humid meadow grassland. An exponential function could be used to fit the GSP–ANPP relationship for the entire region. An improved moisture index that combines the effects of GST and GSP better explained the variations in ANPP compared with GSP alone. In comparisons with the previous studies, we found that the relationships between spatiotemporal variations in ANPP and climate factors were probably scale dependent. We imply that the quantity and spatial range of analyzed samples contribute to these different results. Multi-scale studies are necessary to improve our knowledge of the response of grassland ANPP to climate change.  相似文献